Portable assemblies, systems, and methods for providing functional or therapeutic neurostimulation

ABSTRACT

Neurostimulation assemblies, systems, and methods make possible the providing of short-term therapy or diagnostic testing by providing electrical connections between muscles and/or nerves inside the body and stimulus generators and/or recording instruments mounted on the surface of the skin or carried outside the body. Neurostimulation assemblies, systems, and methods may include a carrier and an electronics pod, the electronics pod including stimulation generation circuitry and user interface components. A power source and/or flash memory may be incorporated in neurostimulation assembly and/or the return electrode. The assemblies, systems, and methods are adapted to provide coordinated neurostimulation to multiple regions of the body.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.12/462,384, entitled “Portable Assemblies, Systems, and Methods forProviding Functional or Therapeutic Neurostimulation,” filed Aug. 3,2009, which is hereby incorporated in its entirety by reference.

U.S. patent application Ser. No. 12/462,384, claims benefit from U.S.Provisional Patent Application No. 61/137,652, entitled “PortableAssemblies, Systems, and Methods for Providing Functional or TherapeuticNeurostimulation,” filed on Aug. 1, 2008, and claims the benefit of U.S.Provisional Patent Application Ser. No. 61/137,652, filed Aug. 1, 2008,and entitled “Portable Assemblies, Systems, and Methods for ProvidingFunctional or Therapeutic Neurostimulation,” both of which are herebyincorporated by reference. U.S. patent application Ser. No. 12/462,384is a continuation-in-part of U.S. patent application Ser. No.11/978,824, filed Oct. 30, 2007, and entitled “Portable Assemblies,Systems and Methods for Providing Functional or TherapeuticNeuromuscular Stimulation,” which is a divisional application of U.S.patent application Ser. No. 11/595,556, filed Nov. 10, 2006, andentitled “Portable Assemblies, Systems and Methods for ProvidingFunctional or Therapeutic Neuromuscular Stimulation,” which claims thebenefit of U.S. Provisional Patent Application Ser. No. 60/801,315,filed May 18, 2006, and entitled “Portable Assemblies, Systems, andMethods for Providing Functional or Therapeutic NeuromuscularStimulation,” which are incorporated herein by reference.

U.S. patent application Ser. No. 12/462,384 is also acontinuation-in-part of U.S. patent application Ser. No. 11/056,591,filed Feb. 11, 2005, and entitled “Portable Assemblies, Systems andMethods for Providing Functional or Therapeutic NeuromuscularStimulation,” which claim the benefit of U.S. Provisional PatentApplication Ser. No. 60/551,945, filed Mar. 10, 2004, and entitled“Steerable Introducer for a Percutaneous Electrode Usable in Associationwith Portable Percutaneous Assemblies, Systems and Methods for ProvidingHighly Selective Functional or Therapeutic Neurostimulation,” which areall incorporated herein by reference.

U.S. patent application Ser. No. 12/462,384 is also acontinuation-in-part of U.S. patent application Ser. No. 11/545,339,filed Oct. 10, 2006, and entitled “Portable Percutaneous Assemblies,Systems and Methods for Providing Highly Selective Functional orTherapeutic Neurostimulation,” which is a continuation of U.S. patentapplication Ser. No. 10/777,771, now U.S. Pat. No. 7,120,499, filed Feb.12, 2004, and entitled “Portable Percutaneous Assemblies, Systems andMethods for Providing Highly Selective Functional or TherapeuticNeurostimulation,” which are all incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

This invention was made with government support under grant no.1R43AR052211-01 awarded by the National Institutes of Health, throughthe National Institute of Arthritis and Musculoskeletal and SkinDiseases. The Government has certain rights in the invention.

FIELD OF INVENTION

This invention relates to assemblies, systems, and methods for providingneurostimulation to tissue.

BACKGROUND OF THE INVENTION

Neurostimulation, i.e., neuromuscular stimulation (the electricalexcitation of nerves and/or muscle to directly elicit the contraction ofmuscles) and neuromodulation stimulation (the electrical excitation ofnerves, often afferent nerves, to indirectly affect the stability orperformance of a physiological system) and brain stimulation (thestimulation of cerebral or other central nervous system tissue) canprovide functional and/or therapeutic outcomes. While existing systemsand methods can provide remarkable benefits to individuals requiringneurostimulation, many quality of life issues still remain. For example,existing systems perform a single, dedicated stimulation function, andare unable to operate in a fashion to provide coordinated stimulation tomultiple regions of a body. Furthermore, these controllers are, bytoday's standards, relatively large and awkward to manipulate andtransport.

There exist both external and implantable devices for providingneurostimulation in diverse therapeutic and functional restorationindications. These neurostimulators are able to provide treatmenttherapy to individual portions of the body. The operation of thesedevices typically includes the use of an electrode placed either on theexternal surface of the skin and/or a surgically implanted electrode. Inthe case of external neurostimulators, surface electrodes and/orpercutaneous lead(s) having one or more electrodes are used to deliverelectrical stimulation to the select portion(s) of the patient's body.

Several clinical and technical issues associated with surface electricalstimulation have prevented it from becoming a widely accepted treatmentmethod. First, stimulation of cutaneous pain receptors cannot be avoidedresulting in stimulation-induced pain that limits patient tolerance andcompliance. Second, electrical stimulation is delivered at a relativelyhigh frequency to prevent stimulation-induced pain, which leads to earlyonset of muscle fatigue. Third, it is difficult to stimulate deepmuscles with surface electrodes without stimulating overlying, moresuperficial muscles resulting in unwanted stimulation. Finally, clinicalskill and intensive patient training is required to place surfaceelectrodes reliably on a daily basis and adjust stimulation parametersto provide optimal treatment. The required daily maintenance andadjustment of a surface electrical stimulation system is a major burdenon both patient and caregiver.

It is time that systems and methods for providing neurostimulationaddress not only specific prosthetic, functional, or therapeuticobjections, but also address the quality of life of the individualrequiring neurostimulation, including the ability to operate aneurostimulation device without concern for replenishing a power source,and to provide coordinated stimulation to multiple regions of a body.

SUMMARY OF THE INVENTION

The invention provides improved assemblies, systems, and methods forproviding prosthetic or therapeutic neurostimulation.

One aspect of the invention provides portable, percutaneous or surfacemounted neurostimulation assemblies, systems and methods that provideelectrical connections between muscles or nerves inside the body andstimulus generators and/or recording instruments temporarilymounted/positioned on the surface of the skin or carried outside thebody.

The assemblies, systems, and methods may, in use, be coupled bypercutaneous leads to electrodes, which are implanted below the skinsurface, or, alternatively, may be coupled to surface mountedelectrode(s), or both, and positioned at a targeted tissue region orregions. The neurostimulation assemblies, systems, and methods applyhighly selective patterns of neurostimulation only to the targetedregion or regions, to achieve one or more highly selective therapeuticand/or functional and/or diagnostic outcomes. The patterns can varyaccording to desired therapeutic and/or diagnostic objectives. Theindications can include, e.g., the highly selective treatment of pain ormuscle dysfunction, and/or the highly selective promotion of healing oftissue or bone, and/or the highly selective diagnosis of theeffectiveness of a prospective functional electrical stimulationtreatment by a future, permanently implanted device. In addition, thecontroller interface from the user to the neurostimulation assemblies,systems, and methods may be wireless or may be manually entered via auser interface on the assembly.

The neurostimulation assemblies, systems, and methods may comprise adisposable patch or carrier. The carrier can be readily carried, e.g.,by use of a pressure-sensitive adhesive and/or covered by a coveringbandage, such as Tegaderm™, without discomfort and without affectingbody image on, for example, an arm, a leg, or torso of an individual. Inplace of worn on the skin, the patch or carrier may also be carried bythe patient, such as in a pocket, or secured to clothing, a bed, or tomovable devices to allow for patient mobility, or alternatively, thecarrier may include a strap to hold the assembly on an arm, a leg, or atorso, for example.

The carrier carries an electronics pod, which generates the desiredelectrical current patterns. The pod houses microprocessor-based,programmable circuitry that generates stimulus currents, time orsequence stimulation pulses, monitors system status, and logs andmonitors usage, for example. The electronics pod may be configured, ifdesired, to accept wireless RF based commands for both wirelessprogramming and wireless patient control.

The electronics pod may also include one or more connection regions, tophysically and electrically couple percutaneous electrode leads and asurface mounted return electrode to the circuitry of the electronicspod, provide access for a programming/communication device, andalternatively provide for networking of multiple assemblies.

The electronics pod and/or the return electrode may further include apower source. The power source provides power to the electronics pod forthe predetermined functional life of the neurostimulation assemblies,systems and methods, which may be hours, days, weeks, months, or up toyears. The power source may comprise a removable or non-removable,replaceable or non-replaceable, and rechargeable or non-rechargeablepower source.

A communication/programming device may be plugged into a matingcommunications interface on the electronics pod, or the neurostimulationassemblies, systems and methods may include a wireless interface to anexternal device. Through this link, a caregiver or clinician canindividually program the operation of a given electronics pod. If needbe, the caregiver or clinician can modulate various stimulus parametersin real time.

Another aspect of the invention provides assemblies, systems, andmethods for providing neurostimulation comprising at least oneelectrode, a disposable carrier sized and configured to be worn by auser, an electronics pod carried on-board the carrier, the electronicspod including circuitry configured to generate a stimulation pulse tothe electrode, and a power source electrically coupled to the circuitry,the power source providing power to the circuitry for the predeterminedfunctional life of the assemblies, systems, and methods.

The electronics pod may also include a visual output, such as a displaycarried on-board the electronics pod and/or visible through theelectronics pod. The visual output can also be provided by anillumination source that illuminates at least a portion of theelectronics pod.

Another aspect of the invention proves systems and methods comprising aneurostimulation assembly. The assembly may include at least oneelectrode sized and configured for implantation in a targeted neural ormuscular tissue region, a lead electrically coupled to the electrode andincluding a connection element adapted to electrically couple to acarrier, the carrier sized and configured to be carried by the patient,an electronics pod removably carried on-board the carrier, theelectronics pod including circuitry configured to generate a stimulationpulse, a power source electrically coupled to the circuitry, a returnelectrode adapted to be electrically coupled to the carrier,instructions prescribing the release and replacement of the returnelectrode according to a preset schedule, and an electrode connectionelement carried on-board the carrier that is electrically coupled to theelectronics pod, the electrode connection element being sized andconfigured to electrically engage at least a portion of the connectionelement of the lead to electrically couple the electrode to theelectronics pod to percutaneously apply the stimulation pulse to thetissue region.

In one embodiment, the carrier is sized and configured to hold the powersource. In another embodiment, the return electrode is sized andconfigured to hold the power source. The power source may be at least onof a non-removable and non-replaceable and non-rechargeable powersource.

Another aspect of the invention provides assemblies, systems, andmethods comprising a surface mounted electrode. The electrode comprisesa top layer and a bottom layer, the bottom layer adapted to provideelectrical contact and adhesion to a patient, a power source positionedbetween the top layer and the bottom layer, and electrically coupled tothe bottom layer and a cable assembly, and a connector electricallycoupled to the cable assembly, the cable assembly and connector adaptedto provide electrical contact between the power source and aneurostimulation assembly.

In one embodiment, at least one conductor of the cable assemblycomprises a carbon-fiber wire. The carbon-fiber wire may be adapted tomake intimate contact with the bottom layer.

In one embodiment, the power source is adapted to be sandwiched betweenlayers of non-conductive material. The layers of non-conductive materialand the power source sandwiched there between may also be sandwichedbetween the top layer and the bottom layer. The power source comprises aflexible power source, and may comprise a capacity of about 1 mA-hr toabout 1000 mA-hr.

In one embodiment, the surface mounted electrode further includesnon-volatile memory positioned between the top layer and the bottomlayer.

Another aspect of the invention provides assemblies, systems, andmethods comprising providing a surface mounted electrode as defined inclaim 1, placing the electrode on a tissue surface, and coupling theelectrode to a neurostimulation assembly.

Other features and advantages of the inventions are set forth in thefollowing specification and attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a neurostimulation assembly thatprovides electrical connections between muscles and/or nerves inside thebody and stimulus generators temporarily mounted on the surface of theskin or carried outside the body.

FIGS. 2A and 2B are views of the neurostimulation assembly shown in FIG.1 worn or carried on a temporary basis on an external skin surface ofthe body.

FIG. 3 is an exploded side view of an embodiment of the neurostimulationassembly shown in FIG. 1, showing its coupling to percutaneous leads toelectrodes, which are implanted below the skin surface in a targetedtissue region or regions.

FIG. 4 is a perspective view of an embodiment of a neurostimulationassembly of the type shown in FIG. 1, showing configurations of coveringbandages to secure the electrodes, lead, and assembly in place for use.

FIG. 5 is a perspective view of an embodiment of a neurostimulationassembly of the type shown in FIG. 1 coupled to an externalprogramming/communication instrument.

FIG. 6 is a perspective view of an embodiment of a neurostimulationassembly of the type shown in FIG. 1 in association with a programmingmode key adapted to allow a clinician access to a programming mode toadjust stimulus parameters and gather/view usage data.

FIG. 7 is a block diagram of an embodiment of a circuit that theneurostimulation assembly shown in FIG. 1 may utilize.

FIG. 8 is a graphical view of a possible biphasic stimulus pulse outputof the neurostimulation assembly for use with the system shown in FIG.1.

FIGS. 9 to 11 show the use of an electrode introducer to percutaneouslyimplant an electrode in a targeted tissue region and for connection to alead extension as shown in FIG. 3.

FIG. 12 is a plan view of an embodiment of a kit packaging theneurostimulation assembly and associated components for use, along withinstructions for use.

FIG. 13 is an anatomical view showing an alternative configuration of aneurostimulation assembly and system, the system including a harnessedmulti-channel stimulation assembly capable of providing coordinatedneurostimulation to multiple regions of the body.

FIG. 14 is an anatomical view of the system shown in FIG. 13, showingthe harnessed multi-channel neurostimulation assembly configured to beheld on a movable stand next to the patient.

FIG. 15 is an anatomical view showing an additional alternativeconfiguration of a neurostimulation assembly and system, the systemincluding a master neurostimulation stimulation assembly and one or moreslave neurostimulation assemblies, with the master assembly capable ofproviding coordinated control of multiple slave neurostimulationassemblies, the system capable of providing coordinated neurostimulationto multiple regions of the body.

FIG. 16 is an exploded view of one embodiment of a surface returnelectrode incorporating a powers source and an optional memory chip.

Although the disclosure hereof is detailed and exact to enable thoseskilled in the art to practice the invention, the physical embodimentsherein disclosed merely exemplify the invention which may be embodied inother specific structures. While the desired embodiment has beendescribed, the details may be changed without departing from theinvention, which is defined by the claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The various aspects of the invention will be described in connectionwith providing neurostimulation for prosthetic or therapeutic purposes.That is because the features and advantages that arise due to theinvention are well suited to this purpose. Still, it should beappreciated that the various aspects of the invention can be applied toachieve other objectives as well.

I. Neurostimulation Assembly Overview

FIG. 1 shows an exemplary embodiment of neurostimulation assembly 10. AsFIGS. 2A and 2B show, the neurostimulation assembly 10 may be sized andconfigured so that, in use, it can be conveniently worn on a temporarybasis. By “worn,” it is meant that the assembly 10 may be removably skinmounted (see FIG. 2A), or may also be carried by the patient (i.e.,user), or secured or strapped (see FIG. 2B) to the patient's arm, leg,waist, clothing, a bed, or to movable devices to allow for patientmobility. By “temporary,” it is meant that the presence of theneurostimulation assembly 10 can be well tolerated without discomfortfor a period of time from several hours to a month or two, or more,after which the neurostimulation assembly 10 can be removed anddiscarded. During the period of use, the neurostimulation assembly 10may be removed and reattached for hygiene maintenance. The assembly 10may be constructed in a manner to conform to the IPX8 standard for wateringress. The assembly 10 may be constructed in a manner to conform tolower water ingress standards as well, for limited water contactapplications.

As FIG. 3 shows, the neurostimulation assembly 10 is, in use, releasablycoupled to a lead 12, including an extension lead 12, with the lead 12coupled to electrode(s) 14 at connector 13. The electrodes 14 may beimplanted, e.g., percutaneously, below the skin surface in a targetedtissue region or regions. The tissue region or regions are targetedprior to implantation of the electrodes 14 due to their muscular and/orneural morphologies in light of desired therapeutic and/or functionaland/or diagnostic objectives.

In use, the neurostimulation assembly 10 generates and distributeselectrical current patterns through the lead 12 to the electrodes 14 andback to a return electrode. In this way, the neurostimulation assembly10 applies highly selective patterns of neurostimulation only to thetargeted region or regions, to achieve one or more highly selectivetherapeutic and/or diagnostic outcomes. As will be described in greaterdetail later, the inputs/stimulation parameters can vary according todesired therapeutic and/or diagnostic objectives. As non-limitingexamples, the outcomes can comprise the highly selective treatment ofpain or muscle dysfunction, and/or the highly selective promotion ofhealing of tissue or bone, and/or the highly selective diagnosis of theeffectiveness of a prospective functional electrical stimulationtreatment.

The neurostimulation assembly 10 will enable a physician to deliver alead 12 and electrode 14, such as a fine wire percutaneous lead 12 andelectrode(s) 14 to target locations via a hypodermic needle and send thepatient home with a skin-mounted or carried or strapped miniatureneurostimulation assembly 10. By delivering the therapy via percutaneouselectrodes 14, the barriers associated with surface stimulation,including cutaneous pain and unreliable electrode placement areeliminated. The use of percutaneous electrodes allows the selective,comfortable, and consistent activation of the muscle(s) (and/or theirinnervating nerves) into which the electrode(s) 14 are implanted.Furthermore, by securing the neurostimulation assembly 10 to the skinnear the treatment site, or strapped near the treatment site, forexample, and eliminating lengthy external cables, the assembly 10 mayenhance the ease of use of electrical stimulation therapy, improvingclinical acceptance and patient compliance.

II. Desirable Technical Features

The neurostimulation assembly 10 can incorporate various technicalfeatures to enhance its usability, which will now be described.

A. The Carrier

In its most basic form (see FIGS. 1 and 3), the neurostimulationassembly 10 comprises a disposable patch or carrier 16. The carrier 16desirably is sized and configured as a compact, lightweight, andflexible assembly made, e.g., of an inert, formed or machined plastic ormetal material.

In a representative embodiment, the carrier 16 may be generally oval andmeasure about 50 mm to about 80 mm in height, and about 30 mm to about60 mm in width, and about 10 mm to about 20 mm in depth, and moreparticularly about 60 mm to about 70 mm in height, and about 40 mm toabout 50 mm in width, and about 12 mm to about 18 mm in depth, or moreor less. The neurostimulation assembly 10 may weigh about 30 grams toabout 50 grams, and more particularly about 40 grams, or more or less.

It is to be appreciated that the neurostimulation assembly 10 andassociated carrier 16 may comprise a variety of sizes, shapes, andweights, for different applications and/or to increase or decrease themounting surface area. At this size, the carrier 16 can be readily wornor carried without discomfort and in a cosmetically acceptable way (asFIGS. 2A and 2B show). The flexible carrier material and shape willallow the neurostimulation assembly 10 to be positioned on curvedsurfaces of the body, such as an arm, shoulder, leg, stomach, and/orback, for example.

B. Securing the Neurostimulation Assembly

The undersurface of the carrier 16 may include an adhesive region 17.The function of the optional adhesive region 17 is to temporarily securethe neurostimulation assembly 10 to an external skin surface during use.For example, an inert, conventional pressure sensitive adhesive or tapecan be used. Desirably, the dermal adhesive region contains abacteriostatic sealant that prevents skin irritation or superficialinfection, which could lead to premature removal.

In place of, or in conjunction with the adhesive region 17, coveringbandage(s) 19 may be used to temporarily secure the neurostimulationassembly 10 in place on the external skin surface. Covering bandages 19may also be used to temporarily secure an extension lead 12, and theelectrode(s) 14 and the extension lead connector 13, to the skinsurface. The use of one or more skin-like covering bandages 19eliminates concerns over lead maintenance and keeps the assembly 10,extension lead 12, and electrodes 14 from snagging during bathing,dressing, or personal grooming, for example.

In place of, or in conjunction with, the adhesive region 17, and/orcovering bandage(s) 19, the assembly 10 may be held in place with theuse of a strap 22. The strap may incorporate velco and/or elastic, forexample, to allow flexibility and comfort when temporarily securing theneurostimulation assembly 10 to the desired body region.

C. The Electronics Pod

The carrier 16 may further carry an electronics pod 20, which generatesthe desired electrical current patterns and may incorporate a connector29 for communication/programming with an external programming system orcontroller 46.

As FIG. 3 shows, the electronics pod 20 can comprise a component or anassembly, such as a molded plastic component or assembly that can besealably secured to the carrier 16. In an alternative embodiment, theelectronics pod 20 may be removable and replaceable on the carrier 16.Having an electronics pod 20 that can be separated from the carrier 16may be desired when the need to replace a carrier 16, or the electronicspod 20, during a course of treatment is necessary. For example,replacement of a carrier 16 without replacement of the electronics pod20 may be desired if the anticipated length of use of theneurostimulation assembly 10 is going to be long enough to expect adegradation of adhesive properties of the adhesive region 17, (if used),or if the adhesive region 17 includes a return electrode, and mayundergo, with use, degradation of adhesive properties and/or electricalconductivity.

Regardless of whether the electronics pod 20 is removable from thecarrier 16, the pod 20 houses microprocessor-based (microcontroller)circuitry 24 that generates stimulus waveforms, time or sequencestimulation pulses, logs and monitors usage, monitors system status, andcan communicate directly to the clinician or indirectly through the useof an external programmer or controller. As a representative example,the stimulation desirably has a biphasic waveform (net DC current lessthan 10 microAmps), adjustable from about 0 mA to about 20 mA based onelectrode type and the tissue type being stimulated, pulse durationsadjustable from about 5 microseconds or less up to about 500microseconds or more, and a frequency programmable from about 1 Hz toabout 150 Hz. Most muscle stimulation applications will be in the 10 Hzto about 20 Hz region, and pain management may use the higherfrequencies. The stimulus current (amplitude) may be user selectable andthe pulse duration may be limited to clinician selectable.

The circuitry 24 desirably includes non-volatile memory, such as a flashmemory device or an EEPROM memory chip to carry embedded, programmablecode 26. The code 26 expresses the pre-programmed rules or algorithmsunder which the stimulation timing and command signals are generated.The circuitry 24 can be carried in a single location or at variouslocations in and/or on the pod 20, and/or return electrode 70, and maybe fabricated on flexible or flex-rigid PC board using a very highdensity technique.

D. Lead Connectors

As FIGS. 1 and 3 show, the electronics pod 20 also includes one or moreconnectors 27, 28, 30. The function of the lead connector 27 is tophysically and electrically couple the terminus of the return electrode18 to the circuitry 24 of the electronics pod 20. In the illustratedembodiments, the lead connector 27 comprises a pig-tail cable extendingoff the electronics pod 20 and ending with a connector 29. It is to beappreciated that the pig-tail cable could-extend off the carrier 16 aswell. It is also to be appreciated that the connector 29 could beintegral with the electronics pod 20 or carrier 16 as well, i.e.,without the pig-tail cable.

Connector 28 physically and electrically couples the terminus of thelead 12, or extension if used, to the circuitry 24 of the electronicspod 20. When multiple channels are used, the connector 28 is able todistribute the electrical current patterns in channels, i.e., eachelectrode 14 comprises a channel, so that highly selective stimulationpatterns can be applied through multiple electrodes 14. One or morechannels may be provided, i.e., two electrodes 14.

Connector 30 may be provided as an option for physically andelectrically coupling a communication/programming device 46 to thecircuitry 24 of the electronics pod 20, i.e., connector 30 can serve asa communication interface. As FIG. 5 shows, the connector 30 can be usedto couple to an external programming device or computer 46. Through thislink 58, information and programming input can be exchanged and data canbe downloaded from the electronics pod 20. This connector may benormally plugged with a rubber seal and only accessed during devicecommunication/programming.

It should be appreciated, of course, that instead of using a cableinterface 58, as shown, a wireless link 59 (e.g., RF magneticallycoupled, infrared, or RF for example) could be used to place theelectronics pod 20 in communication with an external programming device46 or computer.

The connectors 28, 29, and 30 may be touch proof and/or water proofconnectors to help maintain a consistent and reliable electricalconnection. Each connector may be labeled with a number or other indiciato identify the channel of the electronics circuitry 24 that is coupledto each connector.

It is to be appreciated that alternative embodiments are possible.Coupling the extension lead 12, return electrode 18, 70, and device 46to the electronics pod 20 or carrier 16, can be accomplished by alocking motion, a button, or a lever arm, or an Allen drive that ispushed, or slid, or pulled, or twisted, for example.

E. The Power Source

1. Internal Power Source

One embodiment of the power source 32 can be described as aself-contained, limited life power source. The power source 32 maycomprise one or more known power sources, such as capacitor(s) orbattery(ies) 32, e.g., an alkaline, lithium, or Silver Oxide battery toprovide the power to the electronics pod 20 (see FIG. 3). The powersource may be selected based on the predetermined functional life of theassembly 10. As non-limiting examples, embodiments of the assembly 10may be preconfigured for a functional life of one hour, day, week,month, year, two years, five years, or more or less. The power source 32capacity may be sized to match the stimulation output capabilities ofthe assembly 10 for a predetermined amount of time, such as an hour,day, week, month, or year(s), for example. As another non-limitingexample, one embodiment of the assembly 10 may be preconfigured for afunctional life of two months. The power source 32 capacity would besized to match the stimulation output capabilities of the assembly 10for at least the two month period. It is to be appreciated that theneurostimulation assembly 10 may incorporate a wide range of powersource capacities to reduce or extend the predetermined functional lifeof the assembly.

The circuitry 24 may be used to electronically store information aboutthe power source 32. The circuitry 24 may include a non-volatile memory26 to store the power source and other information. The estimatedremaining capacity of the power source 32 may be stored. The circuitry24 may also identify the total power usage (service time) provided todate by the power source.

In one embodiment, the power source 32 may be non-replaceable,non-removable, and/or non-rechargeable. The neurostimulation assembly 10may not require or allow the user to replace the power source 32 for theentire length of the temporary therapy, e.g., the power source capacitymay be sized to function for the predetermined functional life of theassembly and/or the treatment period. Other external stimulators requirethat the user replace and/or recharge a battery as frequently as onceper week. This task can be difficult for post-stroke patients who havecompromised hand function on the hemiplegic side.

The power source 32 may be inaccessible to battery replacement. In oneembodiment, the power source 32 may be secured within the electronicspod 20. The electronics pod 20 may comprise a molded plastic housing,the housing may include multiple pieces and may be made inaccessible bysonic welding, gluing, or other permanent fastening methods, to securethe housing together.

A power budget for the circuitry 24 was developed based on theneurostimulation assembly's performance specifications and expectedoperating characteristics of the key circuit components (based oncomponent specifications). Based on the power budget, a 500 mA-hr to 600mA-hr primary cell battery may provide a service life sufficient for theneurostimulation assembly's performance specifications and expectedoperating characteristics, although it is to be appreciated that smallerand/or larger capacities may be used, such as from about 10 mA-hr toabout 1000 mA-hr, or more or less. Combined with the desired size andshape of the neurostimulation assembly 10, Lithium primary cell typesavailable from domestic suppliers were considered candidates. In oneembodiment, representative battery configurations include two L92 (AAA)1.5V Li/FeS₂ cells in series (each cell is 10 mm diameter×44 mm long);or four ⅓N (⅓ ‘N’ cell size) 3.0V Li/MnO₂ cells in parallel (each cellis 11.5 mm diameter×10.6 mm long).

2. External Power Source

In one embodiment, the return electrode 70, e.g., surface electrode, mayinclude an embedded power source 72, and optionally non-volatile memory,such as flash memory 73. The return electrode 70 may be adapted toprovide power and a return path, and optionally stimulus parametersstored in the memory 73, for the neurostimulation assembly 10. Thereturn electrode 70 may be adapted to provide an electrical connectionto the patient, and provide power to the neurostimulation assembly 10.

One embodiment of the return electrode 70 shown in FIG. 16 may comprisea top layer 74 and a bottom layer 75. The top and bottom layers may betypical of the construction of TENS/NMES return surface electrodes. Thetop layer 74 may be an adhesive-backed fabric, for example, such as anon-woven (i.e., non-porous) medical tape. The bottom layer 75 may be aconductive hydrogel, which provides electrical contact and adhesion tothe patient. The hydrogel may be selected to provide optimal adhesionand electrical properties for desired applications.

The power source 72 may comprise a thin flexible power source, such asis available from Solicore (Lakeland, Fla.). As a non-limiting example,a 25×29×0.5 mm flexible power source with a capacity of 10 mA-hr may beused, although other dimensions and capacities are within the scope ofthe invention for a variety of applications (e.g., 1 mA-hr to 1000mA-hr). The power source 72 and/or the optional flash memory 73 may bepositioned between the top and bottom layers 74, 75. The power source 72and the optional-flash memory 73 may also be sandwiched between onelayer folded or two separate layers, for example, of non-conductivematerial 76, such as an envelope of flexible film. This sandwich of twonon-conductive layers and the power source, and optional flash memory,may then be positioned between the top and bottom layers 74, 75.

A cable assembly 77 may be electrically coupled, e.g., soldered, toexposed terminals 78 of the power source 72, which may also be laminatedbetween the non-conductive material 76. Processes such aspressure-sensitive adhesive, overmolding or hot lamination may be usedto achieve this state. One conductor 79 of the cable assembly 77 maycomprise a carbon-fiber wire, for example, and may exit the laminatedassembly and make intimate contact with the bottom hydrogel layer 75.The cable assembly 77 may also provide the electrical connection incommon with the power source's negative contact. A connector 80, such asa touch proof and/or water proof connector 80, provides electricalcontact between the neurostimulation assembly 10 and the returnelectrode 70.

As previously described, optionally, a flash memory chip 73 may beincluded in the return electrode 70. The memory 73 may, for example,provide a predetermined set of stimulus parameters for theneurostimulation assembly 10. This would allow the disposable powersource/return electrode 70 to also provide the prescription of thestimulus to be delivered.

The novel combination of a power source and return electrode allows theneurostimulation assembly 10 to be reduced in size as no internal powersource is required for the assembly 10. The synergism of integrating thepower source 72 with the return electrode 70 is clear as both may belimited life, disposable items.

The optional inclusion of embedded memory 73, such as a flash memorychip, may permit the clinician to prescribe a predetermined set ofstimulus parameters with just the selection of the proper returnelectrode.

The return electrode with embedded power source takes advantage of oneexample of the usage of the neurostimulation assembly 10, wherein thepatient may be changing their return electrode at predetermined periods,such as every day, or days, or week, or weeks, or months, to provide arenewed source of power with each application. This method allows theneurostimulation assembly 10 to be used indefinitely, as long as asufficient supply of return electrodes 70 is prescribed to the patient.

F. The User Interface

The assembly 10 as shown in FIGS. 1 and 3 desirably includes one or morefeatures that provide an interface mechanism for the patient and/or theclinician. The interface feature allows for the input and output ofneurostimulation assembly information, such as stimulus regimeparameters and system status, and the interface may be manual, audio, orvisual, or a combination. For example, the electronics pod 20 mayinclude control means 38, e.g., two button controls, to allow thepatient to control stimulation amplitude setting or some other stimulusintensity adjustment (up-down; plus-minus; etc.). The electronics pod 20may also be adapted to interface with a programming mode key 37, e.g., amagnet, or a paper clip access switch, for example, to provide controlfor the clinician to access clinician controllable settings through thecontrol means 38, such as the stimulus pulse duration and/or stimulusfrequency and/or stimulus amplitude, for example. As can be seen, theassembly 10 may include a slot or recess 39 adapted to accept theprogramming mode key 37. The programming mode key 37 desirably is inplace in order to switch the neurostimulation assembly 10 into theprogramming mode and access clinician controllable settings.

Table 1 below provides possible stimulus parameter settings. It is to beappreciated that more or less Stimulus Parameters, different ranges ofAssembly Capabilities, and optional Methods of Programming are allwithin the scope of the invention. Table 1 is only intended as anexample of possible settings and capabilities of the neurostimulationassembly 10.

TABLE 1 Neurostimulation Stimulus Parameters Assembly CapabilitiesMethods of Programming Amplitude, 2-20 mA Clinician programmableSustained Pulse Duration, 10-200 μsec Clinician programmable SustainedFrequency 5-80 Hz Factory programmable Duty Cycle 10-100% Factoryprogrammable Ramp Times 0-60 seconds Factory programmable Duty CyclePeriod 15-900 seconds Factory programmable Session Duration 1 minute -Factory programmable continuously # of Sessions 1-1023 sessions Factoryprogrammable per Day Pause Between 1-1023 minutes Factory programmableSessions

In use, the clinician may be able to program the stimulus intensity byinserting the programming key 37 (e.g., a small magnet) into the slot 39molded into the electronics pod 20. Once the key 37 is inserted, theclinician may use pushbuttons 38 on the assembly 10 to evaluate thepatient's response to stimulus intensity settings preconfigured in theassembly. A display 40, e.g., an LCD or LED display on the top of theassembly shows the stimulus intensity being delivered. The clinicianthen selects the optimal stimulus intensity for the patient from theavailable settings.

When the programming key 37 is not inserted, the neurostimulationassembly 10 is in the patient mode and stimulus is automaticallyprovided at the stimulus intensity programmed by the clinician. Thepatient can use the two pushbuttons 38 on top of the assembly to turnthe stimulation off or make minor changes to the stimulus intensityprogrammed by the clinician.

The particular setting level can be displayed using the display 40 tovisually identify to the patient the setting level, and to allow thepatient to record the setting within a therapy diary, which could thenbe presented to a physician for review. The operating modes and stimulusparameters may be entered manually using the control means 38 and/or 37,and easily interpreted via the visual output or feedback display 40. Inone embodiment, the setting level is a combination of pulse duration andamplitude, the specifics of which are unknown to the patient. Thedisplay 40 may also provide a data read-out function for the clinician.For example, the display 40 may provide information such as the totalduration of stimulus provided, the average or median stimulus levelselected by the patient, and perhaps the total duration of nostimulation provided.

The display 40 may also provide status information, such as power sourcestatus or system status. For power source status, the stimulationassembly 10 may indicate the power source 32 has limited powerremaining, or that the power source has provided its maximum amount ofpower, as non-limiting examples. For system status, the stimulationassembly 10 may indicate the electrical connections to the extensionlead 12, electrodes 14, or return electrode 18 are not working, asnon-limiting examples.

In addition to or in place of the visual feedback display 40, visualoutput or feedback may also be provided by an illuminating electronicspod 20, or portions of the electronics pod. The pod 20 may comprise amaterial, e.g., a semi-transparent material, able to allow anillumination source 42, such as one or more LEDs, to create a “glowing”or “illuminated” appearance. The illumination source 42 may be coupledto the circuitry 24 within the electronics pod 20. Status informationcan be visually provided to the user by using various blinking orpulsing configurations, illumination brightness, changing colors, or anycombination, for example. As with the display 40, status information mayinclude power source status and system status.

III. Representative Neurostimulation Assembly Circuitry

FIG. 7 shows an embodiment of a block diagram circuit 90 for theneurostimulation assembly 10 that takes into account the desirabletechnical features of the neurostimulation assembly design discussedabove. The circuit 90 can be grouped into functional blocks, whichgenerally correspond to the association and interconnection of theelectronic components.

In FIG. 7, five functional blocks are shown: (A) the MicroprocessorCircuitry 24; (B) the Power Source 32; (C) the VHH Power Supply 94; (D)the Stimulus Output Stage(s) 96; and (E) the Output Multiplexer 98.

For each of these blocks, the associated functions, and possible keycomponents and circuit description are now described.

A. The Microcontroller Circuitry

The microcontroller circuitry 24 may be responsible for the followingfunctions:

(1) The timing and sequencing of most of the electronics pod 20functions including the generation of stimulus pulses and thequantification of usage by the power source,

(2) A/D converter to measure output pulse, power source voltage, and VHHvoltage,

(3) D/A converter may set the pulse amplitude,

(4) Control for display 40 and/or illumination source 42,

(5) And alternatively, control for a real time clock; the real timeclock to provide a time signal to the microprocessor circuitry from thefirst powering of the electronics pod 20, and keep time without thepresence of the power source 32, 72 for a predetermined amount of time,such as about one hour, day, week, or month, or more or less, asnon-limiting examples.

The use of microcontroller based circuitry incorporating flashprogrammable memory allows the operating software of the neurostimulatoras well as the stimulus parameters and settings to be stored innon-volatile memory (data remains safely stored even when the powersource 32, 72, becomes fully discharged or is removed). The non-volatilememory is also used to store usage history information, and may also belocated in the return electrode 70.

Although the microcontroller circuit 24 may be a single component, thefirmware may be developed as a number of separate modules that deal withspecific needs and hardware peripherals. The functions and routines ofthese software modules may be executed sequentially; but the executionof these modules may be timed and coordinated so as to effectivelyfunction simultaneously. The microcontroller operations that areassociated directly with a given hardware functional block are describedwith that block.

The Components of the Microcontroller Circuit may include:

(1) A single chip microcontroller 25. This component may be a member ofthe Texas Instruments MSP430 family of flash programmable, micro-power,highly integrated mixed signal microcontroller. Likely family members tobe used include the MSP430F1610, MSP430F1611, MSP430F1612, MSP430F168,MSP430F169, and the MSP430FG437. Each of these parts has numerousinternal peripherals, and a micropower internal organization that allowsunused peripherals to be configured by minimal power dissipation, and aninstruction set that supports bursts of operation separated by intervalsof sleep where the microcontroller suspends most functions.

(2) A miniature, quartz crystal for establishing precise timing of themicrocontroller. This may be a 32.768 KHz quartz crystal, for example.

(3) Miscellaneous power decoupling and analog signal filteringcapacitors.

B. Internal & External Power Source

The Power Source 32 and/or 72 (including associated microcontrollercircuitry 24 actions) may be responsible for the following functions:

(1) monitor the battery voltage,

(2) suspend stimulation when the power source voltage becomes very low,

(3) discontinue stimulation when the power source has been used for apredetermined amount of time, e.g., one hour, day, week, month, twomonths, year, or whatever time is prescribed by the clinician, within amargin,

(4) prevent (with single fault tolerance) the delivery of excessivecurrent from the power source, and

(5) provide power to the rest of the circuitry of the neurostimulationassembly, e.g., VHH power supply.

In one embodiment, power management controls are generally included withthe electronics pod 20. As previously described, the circuitry 24 and/orreturn electrode 70 contains non-volatile memory, which is adapted tostore power source usage information written by and read by theelectronic pod 20.

(1) The electronics pod 20 and associated microcontroller circuitry 24may periodically sample the power source 32, and periodically updateusage data, such as the length of time, or the total number of pulsesfor which that the power source has been used. The circuitry 24 may alsobe adapted to read and write power source usage data to the non-volatilememory, 73.

C. VHH Power Supply

The VHH power supply 94 is generally responsible for the followingfunctions:

(1) Provide the stimulus output stage 96 and multiplexer 98, if used,with a programmable DC voltage high enough to drive the requiredcathodic phase current through the electrode circuit plus the voltagedrops across the stimulator stage, and possibly an output couplingcapacitor. VHH is typically about 12 VDC to about 35 VDC.

The Components of the VHH Power Supply might include:

(1) Micropower, inductor based (fly-back topology) switch mode powersupply; e.g., Texas Instruments TPS61045, Texas Instruments TPS61041,Linear Technology LT1615, or Linear Technology LT3459, for example.

(2) The microcontroller circuit 24 monitors VHH for detection of a VHHpower supply failure, system failures, and optimizing VHH for theexhibited electrode circuit impedance.

The actual voltage of the internal stimulus power supply (VHH) may bedynamically adjusted by the stimulator to provide a minimum, butadequate operating overhead voltage for the stimulus output stage 96,thus minimizing the battery power consumption. Although the impedancepresented by the lead 12, electrode 14, and the electrode to tissueinterface varies little over time, the tissue to electrode impedance ofthe surface mounted return electrode 18 may vary and represents themajority of the electrode circuit impedance. A conventional, singleinductor, flyback boost converter circuit topology may be used for theidentified supply and loading conditions. This component may be theSipex SP6691, or comparable switch mode power supply.

D. Stimulus Output Stage

The Stimulus Output Stage(s) 96 is generally responsible for thefollowing functions:

(1) Generate the identified biphasic stimulus current with selectedcathodic phase amplitude, pulse width, and frequency. The recovery phasemay incorporate a maximum current limit; and there may be a delay time(most likely a fixed delay) between the cathodic phase and the recoveryphase (see FIG. 8). Typical currents (cathodic phase) vary from about0.5 mA to about 20 mA based on the electrode construction and the natureof the tissue being stimulated. Electrode circuit impedances can varywith the electrode and the application, but are likely to be less than2,000 ohms and greater than 100 ohms across a range of electrode types.

Two alternative configurations of the stimulus output stage will bedescribed. In the first configuration:

(1) The cathodic phase current through the electrode circuit may beestablished by a high gain (HFE) NPN transistor with emitterdegeneration shunted by switched shunting resistors to form a controlledcurrent sink.

(2) The microcontroller circuit 24 monitors the cathode voltage toconfirm the correct operation of the output coupling capacitor, todetect system failures, and to optimize VHH for the exhibited electrodecircuit impedance; i.e., to measure the electrode circuit impedance.

In a second alternative configuration:

(1) A low-threshold N-channel MOSFET driven by an op-amp with fastenable/disable functions to provide a low quiescent current sink.

(2) A precision voltage reference of about 2.048V for both themicrocontroller circuit external reference and the current sinkreference.

(3) Switched shunting resistors may form the controlled current sink.

(4) The microcontroller circuit 24 monitors the cathode voltage toconfirm the correct operation of the output coupling capacitor, todetect system failures, and to optimize VHH for the exhibited electrodecircuit impedance; i.e., to measure the electrode circuit impedance.

In either configuration, the switched resistors could be replaced by aDAC, if available as an on-chip peripheral at the microcontroller. Ineither configuration, the start and ending of the cathodic phase currentis timed by the microcontroller.

E. The Output Multiplexer

The output multiplexer 98 is required only if more than one electrodecircuit is required. The output multiplexer is responsible for routingthe anode and cathode connections of the Stimulus Output Stage 96 to theappropriate electrode, i.e., electrode(s) 14, and possibly returnelectrode 18, or both.

A representative output multiplexer configuration includes:

(1) A low ON resistance, micropower, dual 4×1 analog multiplexer; e.g.Maxim MAX4052, MAX384, Vishay DG412HS, or Pericom PS4066 or PS323 (withseparate decoding logic or additional microcontroller address lines),for example, and

(2) Microcontroller circuitry 24 selects the electrode connections tocarry the stimulus current (and time the interphase delay) via addresslines.

IV. The Electrodes and their Implantation

The configuration of the electrodes 14 and the manner in which they areimplanted can vary. A representative embodiment will be described, withreference to FIGS. 9 to 11.

In the illustrated embodiment, each lead 12 may comprise a thin,flexible component made of a metal and/or polymer material. By “thin,”it is contemplated that the lead 12 may not be greater than about 0.75mm (0.030 inch) in diameter, although the diameter may be larger orsmaller.

The lead 12 can comprise, e.g., one or more coiled metal wires with inan open or flexible elastomer core. The wire can be insulated, e.g.,with a biocompatible polymer film, such as polyfluorocarbon, polyimide,or parylene. The lead 12 are desirably coated with a textured,bacteriostatic material, which helps to stabilize the electrode in a waythat still permits easy removal at a later date and increases tolerance.

The electrode 14 are electrically insulated everywhere except at one(monopolar), or two (bipolar), or three (tripolar), for example,conduction locations near its distal tip. Each of the conductionlocations may be connected to one or more conductors that run the lengthof the lead 12, proving electrical continuity from the conductionlocation through the lead 12 to the electronics pod 20. The conductionlocation may comprise a de-insulated area of an otherwise insulatedconductor that runs the length of an entirely insulated electrode. Thede-insulated conduction region of the conductor can be formeddifferently, e.g., it can be wound with a different pitch, or wound witha larger or smaller diameter, or molded to a different dimension. Theconduction location of the electrode may comprise a separate material(e.g., metal or a conductive polymer) exposed to the body tissue towhich the conductor of the wire is bonded.

In an alternative configuration, the lead 12 does not utilize anextension 12, rather the lead 12 is electrically connected to theelectronics pod 20 or carrier 16 through an automated connection methodthat connects and terminates the electrode 14.

The electrode(s) 14 and lead 12 are desirably provided in sterilepackages and desirably possess mechanical properties in terms offlexibility and fatigue life that provide an operating life free ofmechanical and/or electrical failure, taking into account the dynamicsof the surrounding tissue (i.e., stretching, bending, pushing, pulling,crushing, etc.). The material of the electrode desirably discourages thein-growth of connective tissue along its length, so as not to inhibitits withdrawal at the end of its use. However, it may be desirable toencourage the in-growth of connective tissue at the distal tip of theelectrode, to enhance its anchoring in tissue.

Furthermore, the desired electrode 14 may also include, at its distaltip, an anchoring element 48 (see FIGS. 10 and 11). In the illustratedembodiment, the anchoring element 48 takes the form of a simple barb orbend. The anchoring element 48 is sized and configured so that, when incontact with tissue, it takes purchase in tissue, to resist dislodgementor migration of the electrode out of the correct location in thesurrounding tissue. Desirably, the anchoring element 48 is preventedfrom fully engaging body tissue until after the electrode 14 has beendeployed. The electrode is not deployed until after it has beencorrectly located during the implantation (installation) process, aswill be described in greater detail later.

In one embodiment, the lead 12 can include a metal stylet within itscore. Movement of the stylet with respect to the body of the electrodeand/or an associated introducer (if used) is used to deploy theelectrode by exposing the anchoring element 48 to body tissue. In thisarrangement, the stylet is removed once the electrode 14 is located inthe desired region.

In the illustrated embodiment (see FIGS. 10 and 11), an electrode 14 maybe percutaneously implanted housed within electrode introducer 50 (i.e.,a hypodermic needle). The electrode introducer 50 comprises a shafthaving sharpened needle-like distal tip, which penetrates skin andtissue leading to the targeted tissue region. The lead 12 may be loaded(it may be preloaded and provided in a kit) within a lumen in theintroducer 50, with the anchoring element 48 shielded from full tissuecontact within the shaft of the introducer 50 (see FIG. 9). In this way,the introducer can be freely manipulated in tissue in search of adesired final electrode implantation site (see FIG. 10) before deployingthe electrode and withdrawing the introducer 50 (see FIG. 11).

The electrode introducer 50 may be insulated along the length of theshaft, except for those areas that correspond with the exposedconduction surfaces of the electrode 14 housed inside the introducer 50.These surfaces on the outside of the introducer 50 are electricallyisolated from each other and from the shaft of the introducer 50. Thesesurfaces may be electrically connected to a connector 64 at the end ofthe introducer body (see FIGS. 9 and 10). This allows connection to astimulating circuit 66 (see FIG. 9) during the implantation process. Thestimulating circuit 66 may comprise a stand along stimulator, or theneurostimulation assembly 10 may be the stimulating circuit. Applyingstimulating current through the outside surfaces of the introducer 50provides a close approximation to the response that the electrode 14will provide when it is deployed at the current location of theintroducer 50.

The electrode introducer 50 is sized and configured to be bent by handprior to its insertion through the skin. This will allow the physicianto place an electrode 14 in a location that is not in an unobstructedstraight line with the insertion site. The construction and materials ofthe electrode introducer 50 allow bending without interfering with thedeployment of the lead 12 and withdrawal of the electrode introducer 50,leaving the electrode 14 in the tissue.

V. Installation of the Neurostimulation Assembly

Prior to installation, a clinician identifies a particular muscle(s)and/or neural region(s) to which a prescribed therapy using theneurostimulation assembly 10 will be applied. Once the particularmuscle(s) and/or nerve(s) and/or tissue region or regions areidentified, the clinician proceeds to percutaneously implant one or moreelectrodes 14 and leads 12, one by one, through the desired skin region68. While each electrode 14 is implanted, the electrode introducer 50applies a stimulation signal until a desired response is achievedindicating the desired placement, at which time the electrode 14 isdeployed and the introducer 50 is withdrawn.

Upon implanting each electrode (see FIG. 4, for example), the clinicianis able to route the extension lead 12, if used, to a lead connector 28on the electronics pod 20 (or carrier 16).

The following illustration will describe the use of a neurostimulatorassembly 10 that will be carried or worn on the patient's exterior skinsurface. It is to be appreciated that the neurostimulator assembly 10could be carried by the patient or temporarily secured to a bed or otherstructure and the lead extensions 12 extend to the assembly 10. Theassembly 10 is placed around an arm or leg (e.g., with the use of astrap), or on the skin in a desirable region, that allows electricalconnectivity to the electrode(s) 14, lead 12, and associated connector28 (see FIGS. 2A through 3). The carrier 16 may be secured in place withpressure sensitive adhesive 18 on the bottom of the carrier 16, or heldin place with a covering tape, or with a strap, as previously described.As previously stated, the adhesive region desirably contains abacteriostatic sealant that prevents skin irritation or superficialinfection, which could lead to premature removal.

After implanting one or more electrodes 14 and placing a returnelectrode 18, 70, on the skin surface, the clinician would be able toroute the lead 12 to the electronics pod 20, and couple the returnelectrode to the connector 29 to complete the stimulation path. Theneurostimulation assembly 10 is ready for use.

VI. System Kits

As FIG. 12 shows, the various devices and components just described canbe consolidated for use in one or more functional kit(s) 82. The kit cantake various forms. In the illustrated embodiment, the kit 82 comprisesa sterile, wrapped assembly. The kit 82 includes an interior tray 86made, e.g., from die cut cardboard, plastic sheet, or thermo-formedplastic material, which hold the contents. Kit 82 also desirablyincludes instructions for use 56 for using the contents of the kit tocarry out a desired therapeutic and/or diagnostic and/or functionalobjectives.

The instructions 56 can, of course vary. The instructions 56 shall bephysically present in the kits, but can also be supplied separately. Theinstructions 56 can be embodied in separate instruction manuals, or invideo or audio tapes, CD's, and DVD's. The instructions 56 for use canalso be available through an internet web page.

The arrangement and contents of the kit 82 can vary. For example, FIG.12 shows a kit 82 containing the neurostimulation assembly 10. Theinstructions for use 56 in the kit 82 may direct a clinician to placethe neurostimulation assembly 10, implant the electrode 14, couple theelectrode 14 to the lead 12, couple the lead 12 to the assembly 10, andplace the return electrode 18 and couple the return electrode to theassembly 10. The instructions may also include instructions for the userin the operation of the neurostimulation assembly 10. Kit 82 may alsoinclude an extension lead 12, and one or more electrodes 14.

As FIG. 5 shows, external desktop or handheld (desirably also batterypowered) preprogrammed and/or programmable instruments 46 can be used toprogram stimulus regimes and parameters into the neurostimulationassembly 10, or to download recorded data from the neurostimulationassembly 10 for display and further processing. Instructions for use 56may describe options for the instruments 46 to communicate with theneurostimulation assembly 10, e.g., by a cable connection 58, wirelesscoupling 59, e.g., by radio frequency magnetic field coupling, byinfrared, or by RF wireless, for example. The communications cable 58may be adapted to provide power to the neurostimulation assembly 10during programming, as well as communications with the circuitry 24 ofthe neurostimulation assembly 10. The external programming instrument 46can also be a general purpose personal computer or personal digitaldevice fitted with a suitable custom program and a suitable cable orinterface box for connection to the communications cable 58.

The programming instruments 46 allow a clinician one option forcustomizing the stimulus parameters and regime timing residing in anindividual neurostimulation assembly 10 according the specific needs ofthe user and the treatment goals of the clinician. The neurostimulationassembly 10 can, once customized, be disconnected from the programmingsystem, allowing portable, or skin worn operation, as already described.The programming instruments also allow the retrieval of usageinformation allowing the clinician to accurately assess patientcompliance with the prescribed treatment course or regime.Alternatively, and as previously described, the clinician may use thepush buttons 38, display 40, and/or access through the use of theprogramming mode key 37 to program the stimulus parameters and timingand to retrieve key usage data.

The foregoing is considered as illustrative only of the principles ofthe invention. Furthermore, since numerous modifications and changeswill readily occur to those skilled in the art, it is not desired tolimit the invention to the exact construction and operation shown anddescribed. While the preferred embodiment has been described, thedetails may be changed without departing from the invention, which isdefined by the claims.

1. A surface mounted electrode comprising: a top layer and a bottomlayer, the bottom layer adapted to provide electrical contact andadhesion to a patient, a power source positioned between the top layerand the bottom layer, and electrically coupled to the bottom layer and acable assembly, and a connector electrically coupled to the cableassembly, the cable assembly and connector adapted to provide electricalcontact between the power source and a neurostimulation assembly.
 2. Anelectrode according to claim 1: wherein at least one conductor of thecable assembly comprises a carbon-fiber wire.
 3. An electrode accordingto claim 2: wherein the carbon-fiber wire is adapted to make intimatecontact with the bottom layer.
 4. An electrode according to claim 1:wherein the top layer comprises an adhesive-backed fabric.
 5. Anelectrode according to claim 1: wherein the bottom layer comprises aconductive hydrogel material adapted to be placed on the skin.
 6. Anelectrode according to claim 1: wherein the power source is adapted tobe sandwiched between layers of non-conductive material.
 7. An electrodeaccording to claim 1: wherein the layers of non-conductive material andthe power source sandwiched there between is sandwiched between the toplayer and the bottom layer.
 8. An electrode according to claim 1:wherein the connector is touch proof and/or water proof.
 9. An electrodeaccording to claim 1: wherein the power source comprises a flexiblepower source.
 10. An electrode according to claim 1: wherein the powersource comprises a capacity of about 1 mA-hr to about 1000 mA-hr.
 11. Anelectrode according to claim 1: further including non-volatile memorypositioned between the top layer and the bottom layer.
 12. A methodcomprising: providing a surface mounted electrode as defined in claim 8,placing the electrode on a tissue surface, and coupling the electrode toa neurostimulation assembly